Bleaching wood, removing tannin?

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soundkite
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Joined: Fri Aug 18, 2017 3:09 am

Bleaching wood, removing tannin?

Post by soundkite » Thu Nov 16, 2017 8:48 pm

Now that I'm having success with V bit inlays, I'm playin with staining techniques, including darkening via the iron acetate method (steel wool + vinegar). Since this technique works by reacting with tannins, could I successfully remove tannin from the wood I don't want to stain? My googling has been fruitless, except for many links to aquarium enthusiasts who say to boil wood to remove the tannins so it doesn't turn the fish tank yellow. Has anyone tried this or know if boiling wood (or other method) would remove enough tannins to make a difference? I think this will be my weeknd project!

DanMc
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Re: Bleaching wood, removing tannin?

Post by DanMc » Fri Nov 17, 2017 2:05 am

I've used oxalic acid to bleach wood, in my case the effect was mild and I'm not sure if it actually reduced tannins. There are 2 part bleaches which are supposed to be stronger but I have no personal experience. Google wood bleach. This stuff is all water based, mixing chemicals with water so I'm not sure how much control you'd have as it will leach into the wood.

madhatter
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Location: WA, USA

Re: Bleaching wood, removing tannin?

Post by madhatter » Fri Nov 17, 2017 4:49 pm

What about going the other way. I just watc[*]hed this video on using ammonium chloride and a heat gun to chemically burn wood. If you are wanting to only stain the engraved areas, the process below might work.

EDIT: Coat with waterproof sealer to stop the ammonium chloride from soaking in on the non-engraved parts.
Do the V-bit engraving
Lightly mist the entire engraved area with the amonium chloride mix
Let dry
Sand the surface to remove ammonium chloride waterproof finish (if you want).
Use heat gun to burn the engraved areas

Just a thought. I haven't done it, but I did order some of the ammonium chloride from Amazon just last night. I plan on making a stamp and burning my (not yet finished) logo on my products.
Last edited by madhatter on Fri Nov 17, 2017 9:58 pm, edited 2 times in total.
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winters636
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Re: Bleaching wood, removing tannin?

Post by winters636 » Fri Nov 17, 2017 6:05 pm

Madhatter, that is awesome and I am definitely going to try it out as well.

Will this work with all species of wood?

madhatter
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Re: Bleaching wood, removing tannin?

Post by madhatter » Fri Nov 17, 2017 9:55 pm

Oh, man, I have no idea. I just ordered the stuff myself last night, so I have no idea.

After thinking about it, I think I would apply a sealer or waterproof finish to the wood before engraving so there will need to be less sanding, just in case the ammonium chloride soaks in farther than you want to sand.
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RICKXX70
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Re: Bleaching wood, removing tannin?

Post by RICKXX70 » Sun Dec 10, 2017 12:59 pm

Best product I've used for bleaching wood. FOOD GRADE PEROXIDE. 30-35%
I apply with spray bottle.. very corrosive so don't have anything around that might corrode if it comes into contact with the residue spray...
12-24 hours bleachtime or 1-2 days.. then I take a cup - 12 oz. of distilled water and heat it to boiling. Than ad 1-1/2 table spoons baking soda.... what the magic. Than use this solution to wipe the wood surface with lint free rag to remove any residues left over.

Been using this method on my Pyrography wood burns and anytime I need to bleach any wood.
Work a lot with solid Birch and Russian Baltic Buch ply.. turns it white..

Removes a lot of surface residue otherwise unseen.

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